#include<bits/stdc++.h>
#define ll long long
#define L x<<1
#define R L|1
#define mid (l+r>>1)
#define lc L,l,mid
#define rc R,mid+1,r
#define OK y^fa&&!vis[y]
#define Root 1,1,n
#define rep(x,y,z) for(int x=(y);x<=(z);x++)
#define per(x,y,z) for(int x=(y);x>=(z);x--)
#define repn(x) rep(x,1,n)
#define repm(x) rep(x,1,m)
#define pb push_back
#define e(x) for(int i=h[x],y=to[i];i;i=nxt[i],y=to[i])
#define E(x) for(auto y:p[x])
#define Pi pair<int,int>
#define ui unsigned ll
inline int read(){int s=0,w=1;char c=getchar();while(c<48||c>57) {if(c=='-') w=-1;c=getchar();}while(c>=48&&c<=57)s=(s<<1)+(s<<3)+c-48,c=getchar();return s*w;}
inline void pf(ll x){if(x<0) putchar('-'),x=-x;if(x>9)pf(x/10);putchar(x%10+48);}
using namespace std;
const int N =1e3+5,M=1e6+5,inf=(1LL<<30)-1,mod=1e9+7;
const ll llf=1e18;
inline void add(int &a,int b){((a+=b)>=mod) and (a-=mod);}
inline int Add(int a,int b){return add(a,b),a;}
inline int mul(int a,int b){return 1LL*a*b%mod;}
inline void Mul(int &a,int b){a=mul(a,b);}
inline void red(int &a,int b){add(a,mod-b);}
inline int Red(int a,int b){return red(a,b),a;}
inline int qp(int a,int b){if(!b)return 1;int c=qp(a,b>>1);Mul(c,c);if(b&1)Mul(c,a);return c;}
inline int INV(int x){return qp(x,mod-2);}
const ui base=13331;
int n,m,a[N],b[N],c[N];
inline int get1(int s){
	int ans=0;
	while(s)ans++,s-=s&-s;
	return ans;
}
map<ui,int>P;
inline void subtask0(){
	int S=(1<<m)-1;
	rep(s,0,S)if(get1(s)==n-1){
		int na=1,nb=1;
		repm(i)if((s>>i-1)&1)c[i]=b[nb],na++;
		else c[i]=a[na],nb++;
		ui H=0;
		repm(i)H=H*base+c[i];
		P[H]=1;
	}
	cout<<(int)P.size();
}
inline void Main(){
	n=read(),m=n*2-2;
	repn(i)a[i]=read();
	repn(i)b[i]=read();
	if(n<=10)return subtask0(),void();
}
signed main(){
	freopen("zha.in","r",stdin);
	freopen("zha.out","w",stdout);
	int T=1;
	while(T--)Main(); 
	return 0;
}
